Piston.



PATBNTEDJAN. 30, 1906.

G. H. STALLMAN.

PISTO N. APPLroA'rIoN FILED APR.5,1905.

IIIII" l TTORNEY.

' UNITED STATES To all whom it may concern:

Be it known that I, GRANVILLE H. STALL- MAN, a citizen of the United States, and a resident of the city and county of Philadelphia, State of Pennsylvania, have invented certain new and useful Improvements in Pistons, of which the following is a specification. My invention relates to improvements in pistons, and more particularly toimprovements in the self-adjusting pistons used in sausage-filling and likemachines, where it is desirable to employ a single-acting rodless '"7 iston; and the object of my invention is to 'sh an improvement in the construction I 5 fof this class of pistons, as fully set forth here- 'inaften faa The accompanying drawing shows a central vertical section through a piston of my construction and a similar view of part of a cyl- 2o inder in which the piston is placed'. va is the cylinder. j *The piston proper is constructed in two "parts, a main portion b and a secondary portion c. The main portion b is furnished with p a head d, with sides k, and with a central web ff', 0r hub e, the upper end of which is bored out, i as shown at f, and the lower portionof which is drilled to receive loosely a bolt g, the lower end of which is adapted to be screwed into the secondary portion ci In order to hold the bolt g and the portion cin place, the former carries a nut or head h, which is adapted l to rest upon the seat fnrmed by the under Il side of the openingf. l

'gro

'i is a lu closin the to of the o enin The slidegof the gsecondeii'y portiolii c tlizirt faces the main portion b of the piston is furl lashed with a aange j, which is adapted to pass between the cylinder a and the sides 7c of 4o the main portion of the piston and to bear Specification of Letters Patenti,

Application filed April 6, 1905. Serial No. 254,253.

PWALENT OFFICIR GRANVILLE H. STALLMAN, OF PHILDELPHIA, IENNSYLVANIA.A

PISTON.

Patented Jan. 30, 1906.

against the elastic packing l, which surrounds the main portion of the piston, as shown, and which at its upper end bears against a shoulder m, forme The actuating fluid being admitted'to the under part of the cylinder a engages the under side of the portion c of the piston, raises it and the bolt g, and causes the flange j to engage the under end of the elastic pac ring l, which is expanded, making a perfectly tight joint between the piston and cylinder. As soon as the pressure of the actuating fluid is relieved the portion c of the piston falls and the packing l contracts, permitting the piston to fall freely or to follow the actuating iluid as it is drawn from the lower end of the cylinder.

I am aware that pistons have been before made with a loose portion corresponding Vto my portion c for expanding an elastic packy the head d.

ing between the main portion of the piston V and the sides of the cylinder, and hence I do not claim this feature broadly; but

What I do claim is- In a piston, in combination, a main portion consisting of a head, sides, and a central web or hub, the latter of -whichiswbored and drilledlohlgitidinall amlrfor e upp ored or ion of said web or hlib, a movable flanged Bead, `a bolt/secured to said head and passin through the drilled portion of said web, a ead or nut on said bolt, and an elastic packing surrounding the main portion of said piston resting upon the fiange of the-movable head.

GRANVILLE H. STALLMAN.

Witnesses GEORGE W. SELTZER, CHARLES A. BUTTER. 

